1. Field of the Invention
The present invention relates to electrical connectors. More specifically, the present invention relates to a contact for an electrical component socket.
2. Brief Description of Earlier Developments
Electrical components, such as integrated circuit (IC) chips, must be secured to a substrate. One example of an interconnection system for securing such pin grid array (PGA) components to a substrate is a zero insertion force (ZIF) system. In ZIF systems, pins of the PGA component enter an interconnect housing without engaging contacts of the interconnect mounted to the substrate. Only after the PGA component seats on the interconnect housing are the contacts and pins engaged.
One method of engaging the contacts and PGA pins involves moving the PGA pins laterally and into engagement with the contacts. An actuating lever and a cam surface drive an interposer assembly laterally to propel the PGA pins. The interposer assembly moves the PGA pins towards, and into connection with, the contacts.
The housing used with such ZIF interconnects encounters loading during, and after, lever actuation. The forces required to deflect the contacts in order to receive the PGA pins determines the amount of loading on the housing. The greater number of contacts increases the peak, or maximum force required to mate the contacts and PGA pins. It is estimated that an interconnect with 500 contacts requires approximately twenty (20) pounds of force to mate the contacts and PGA pins successfully.
Technological advances have increased the pin count and contact density of PGA components and have miniaturized computer components (requiring reduced profile sizes). While the improved speed may satisfy consumers, these technological advances burden conventional ZIF sockets. Often, a design that compensates for one of the above technological advances is mutually exclusive to a design that compensates for another technological advance.
In one example of a modification, a designer may increase the number of holes in the socket and decrease the pitch between the holes to account for increased pin density and the pin count. However, this reduces the strength of the socket.
In another example of a modification, a designer may shorten the contact to account for reduced profile size. A shorter contact exhibits greater stiffness, thus increasing the required insertion force to mate with the PGA pins.
These two design objectives impose conflicting requirements, since a stiffer contact requires more actuation force on the lever. A larger actuation force increases the loading on the socket. But the reduced strength of the socket (due to the increased hole count and decreases pitch) renders the socket less likely to withstand the increased loading.
The increased contact density has also taxed the capabilities of conventional contact forming methods. The typical method of forming opposed dual beam contacts is to stamp the contact from a sheet of material. However, the width of the sheet material required to form a single contact with conventional techniques will exceed the pitch requirements imposed by these technological advances.
It is an object of the present invention to provide an improved device for connecting an electrical component to a substrate.
It is a further object of the present invention to provide a socket for an electrical component that exhibits lower peak insertion force.
It is a further object of the present invention to provide a socket for an electrical component that selectively mates only a portion of the contacts at a time.
It is a further object of the present invention to provide a device for connecting an electrical component to a substrate that sequentially mates contacts in columns.
It is a further object of the present invention to provide a socket for an electrical component that accommodates larger pin counts.
It is a further object of the present invention to provide a device for connecting an electrical component to a substrate that precisely aligns the mating contacts during rotation.
It is a further object of the present invention to provide a contact with in-line dual beams.
These and other objects of the present invention are achieved in one aspect by a contact. The contact has a retention portion, a tail portion and a pair of beams. The retention portion has opposed ends and defines a plane. The tail portion extends from one end of the retention portion. The pair of beams extend from the other end of the retention portion. Each of said pair of beams has a first portion and a second portion. The first portion displaces the beam from the plane of the retention portion, with each beam located on opposite sides of the plane of the retention portion. The second portion extends from, and is canted relative to, the first portion. The second portion has a contact interacting portion. The contact interacting portions of both beams interact to receive a contact therebetween.
These and other objects of the present invention are achieved in another aspect by a method of making a contact. The contact has a retention portion for engaging a connector housing, a tail portion extending from one of the ends, and a pair of beams extending from the other end. The retention portion has opposed ends and defines a plane. The method includes the steps of: displacing a first portion of the beams from the plane of the retention portion so that the pair of beams are located on opposite sides of the plane; and canting a second portion of the beams relative to said first portion to provide a contact interacting portion adapted to receive a mating contact therebetween.
These and other objects of the present invention are achieved in another aspect by a dual beam contact. Each beam has a proximal end and a distal end for engaging a male-type contact. The proximal ends are generally coplanar and the distal ends are aligned so as to receive the male-type contact therebetween.